1. Field of the Invention
The present invention relates to controls for air conditioners. More specifically the present invention relates to a combination thermostat and blower speed control for use with an air conditioner which has both heating and cooling modes of operation, typically a hot air furnace in combination with a refrigeration unit.
2. Prior Art
Combination thermostat and blower speed controls have been used to provide safe and efficient operation of a hot air furnace having in combination therewith a refrigeration unit. Typically the thermostat section of the control senses a cooling need or heating need within the enclosure to be conditioned. A blower speed switch has been provided as part of the control wherein the blower speed may be selected to operate either continuously or on an automatic basis when conditioning is required.
Typical examples of combination thermostat and blower speed control circuits include U.S. Pat. Nos. 3,554,003, 3,587,558 and 3,664,414; all issued to the assignee hereof. These patents all include a system switch connected to the thermostat for selecting the appropriate mode of operation and a blower speed switch for selecting either continuous single speed blower operation or automatic blower operation when conditioning is required.
None of the cited art discloses the use of a multi-speed blower switch electrically connected to a system switch, such that upon cooling being required, the blower speed switch will be overridden so that the blower will be operated at high speed (cooling speed) notwithstanding the selection of blower speed at the blower speed switch. The advantages of this control method include the availability of continuous low speed operation of the blower for circulating air throughout the enclosure when the thermostat is set in the cooling mode of operation but the cooling system is idle. When the unit is providing cooling the blower will then be operated at high speed. After the cooling is discontinued the control will allow the blower to return to continuous circulation at low speed without subsequent control changes. All of this regulation of operation can be accomplished from the thermostat remote from the furnace.